Method and system for creating, viewing, editing, and sharing output from a design checking system

ABSTRACT

Existing text output from a design rule checker is put in appropriate input format, and automatically displayed as text within a design tool using existing design tool capabilities, such as highlighting, zooming, and drawing box-regions. A graphical display of the output of the rule checker includes the informative text. Design rule violations are listed in a manner in which they can be individually selected. The output is displayed on a unique software program layer within the design tool so as to not effect or make any permanent changes to the original design file. The layers can be safely deleted when no longer in use.

BACKGROUND OF INVENTION

This invention relates to the field of printed feature manufacturing,such as printed circuit boards and integrated circuitry manufacturing.In particular, this invention relates design tools for printed circuitboard layouts and integrated device layouts. More specifically, theinvention relates to graphically identifying each violation of a designrule to a user using the output of a design rule checker.

Computer aided design (CAD) software programs are used to create designdrawings such as electrical schematics. To fabricate either a printedcircuit board or an integrated circuit (IC), engineers first use alogical electronic design automation (EDA) tool, to create a schematicdesign, such as a schematic circuit design or layout. The layouttypically contains data layers that correspond to the actual layers tobe fabricated in the circuit board or circuit. Such designs usually haveto adhere to a set of predefined criteria, referred to as design rules,which are unique to the product, product type, or manufacturing process.Various techniques have been developed to ensure conformance to designrules. These techniques include the use of design rule checking programsrun subsequent to the design creation and the use of interactive designrule checking procedures run continually during the design process.

Once the layout is created, the layout is verified to ensure that thelayout has been properly executed and that the final layout createdadheres to certain geometric design rules. These layout verificationsare called design rule checks. Such tools are available from CADENCEDESIGN SYSTEMS and from MENTOR GRAPHICS. In these tools a number ofphysical design rule checkers exist. These rule checkers compare actualdesign data against a user or default-specified set of design parametersand output any non-complying features as violations. When anomalies orerrors are discovered by these checking tools, the designer must repairthe fault before the layout is sent out for circuit manufacturing andwafer fabrication. Design rule checking searches the design forviolations of a predetermined set of conditions, for example, minimumline widths and minimum separations, and returns a result indicatingwhether design rule violations were found. The intermediate layer(s)associated with a design rule checker can store a list of design ruleerrors found, or a modified design that satisfies the design rules.

The design rule checker is typically a software program or module, whichis provided by an established vendor or specially programmed. The designrule checker is adapted to receive a digital representation of thelayout pattern to be analyzed. Such representations specify in astandard format the coordinates of defined edges on a pattern or othergeometric features. Generally, the layout design is provided in adigital form to a design rule checker set to select only those featuresthat violate the design rules. In U.S. Pat. No. 6,282,696 issued toGarza, et al., on Aug. 28, 2001, entitled “PERFORMING OPTICAL PROXIMITYCORRECTION WITH THE AID OF DESIGN RULE CHECKERS,” a design rule checkeris used to locate features of an integrated circuit layout designmeeting predefined criteria. A partial layout is created as a new filehaving coordinates for each small feature under consideration. However,graphical assistance in dealing with violations identified by the designrule checker is neither taught nor suggested.

One problem with these design rule checkers is that a majority of themoutput the violations as a text file. Reviewing the output of thesedesign rule checkers requires significant time on the part of the userto locate and understand the violation by using the text output tomanually interact with the design file. A few design rule checkers alsooutput some graphical information, but in most cases this information islimited to a pointer that identifies a problem location withoutproviding data related to any specifics about the violation. An exampleof this type of output is demonstrated by the CADENCE ALLEGRO™ DRC(design rule checker). In these types of systems, the location of theviolation is given, but useful information concerning the violationremains unknown to the user.

In U.S. Pat. No. 6,415,421 issued to Anderson, et al., on Jul. 2, 2002,entitled “INTEGRATED VERIFICATION AND MANUFACTURABILITY TOOL,” ahierarchical database is taught to store shared design data accessed bymultiple verification tool components, such as design rule check. Thedatabase includes representations of one or more additional, orintermediate layer structures that are created and used by theverification tool components for operations performed on the designbeing verified. Once again, however, graphical representations ofviolations are not suggested or taught.

Generally, the output of design rule checkers is a one-time-only output,either in a text file or in a view of the design file within the designenvironment. There are no utilities within the violation review processfor a user to create a desired subset of those violations that couldthen be shared with a designer. The user is typically forced to manuallyedit the original text output and give the resulting list to thedesigner, who must repeat the process of manually locating andunderstanding the violations. Often, when reviewing a list ofviolations, the user needs to obtain more information about a particularviolation, such as inquiring about the neighboring features or some ofthe properties associated with the violating feature. With traditionalviolation reviewing, the user enters a number of keystrokes to get thisinformation. If in the process of obtaining this information, the viewof the design changes significantly, such as scrolling to a differentlocation within the design, manual effort is required to relocate theviolation in question.

Consequently, there is a need in the art to take the output of a designrule checker and graphically identify each violation to the user usingdesign tool operations.

Bearing in mind the problems and deficiencies of the prior art, it istherefore an object of the present invention to provide a graphicalmethod for viewing and editing output from a design rule checkingsystem.

It is another object of the present invention to provide a system andmethod that takes a text file from a design rule checker and graphicaldisplays violations to a user.

A further object of the invention is to provide an interactive graphictool using the output of a design rule checker to allow multiple usersto view output without re-running the rule checking software.

It is yet another object of the present invention to provide anon-destructive interactive graphical tool to allow a designer to workwith design rule checking output without risking existing data.

Another object of the present invention is to allow a user to view adesign violation from any rule-checking tool that outputs in compatibleformat.

Still other objects and advantages of the invention will in part beobvious and will in part be apparent from the specification.

SUMMARY OF INVENTION

The above and other objects, which will be apparent to those skilled inart, are achieved in the present invention which is directed to a methodof using text from a design tool to display an output to a user, themethod comprising: graphically displaying the output from the text ofthe design tool; graphically listing design rule violations; displayingthe output as part of a software layer of the design tool such that nopermanent changes are made to any original design file; generating andannotating a subset output file for use by other users; and generatingsoftware help functions allowing the user to gain information aboutdesign rule violations. The design tool may be a design rule checkingsystem. The text comprises text output from the design tool. The textoutput from the design tool comprises an input file for softwareimplementing the method. The method further includes individuallyselecting the design rule violations. The output may be represented aspart of the software layer of the design tool and deleted when no longerrequired. The software layer may be presented in a pop-up windowdisplay. The pop-up window includes information identifying the designrule violations, net name, component name, information relating todesign rules. The pop-up window further comprises the identification ofparameters being checked along with information as to the parameters'importance. The method may include drawing a bounding box around any ofthe design rule violations. The subset output file may be loaded andviewed without running the design tool rule checker. The subset file mayinclude saved information relating to an identified violation. The savedinformation may be shared electronically with different users. Theidentified violation may be requested by the user to be saved such thata resulting output file contains only those of the design ruleviolations that the user requested be saved, preserving the originaldesign file. Software help functions may include highlighting, zooming,measuring cumulative distance between multiple points, changingviewpoints of a design, changing magnification level, changing featurevisibility, and changing location of a viewport. The design ruleviolations may be reselected to return to an originally presented view.

In a second aspect, the present invention is directed to a method ofviewing violations identified by a design rule checker comprising:inputting text output from the design rule checker into a softwareprogram routine for viewing the violations; inputting design fileinformation into the software program routine; generating a subsetoutput file of the violations for a user to view; and editing the designfile based on the violations. The method may further comprise: inputtingdesign data and rule checker parameters into a design rule checkingtool; and performing design rule checking. The method includesgenerating a subset text output file of the violations and allowing theuser to individually select the violations. The output may berepresented as part of a software layer of the design rule checker, anddeleted when no longer required. The software layer may be presented ina pop-up window display.

In a third aspect, the present invention is directed to a programstorage device readable by a machine, tangibly embodying a program ofinstructions executable by the machine to perform method steps for usingtext from a design tool to display an output to a user, the method stepscomprising: graphically displaying the output from the text of thedesign tool; graphically listing design rule violations; displaying theoutput as part of a software layer of the design tool such that nopermanent changes are made to any original design file; generating andannotating a subset output file for use by other users; and generatingsoftware help functions allowing the user to gain information aboutdesign rule violations. The text comprises text output from the designtool. The text output from the design tool comprises an input file forsoftware implementing the method. The design rule violations may beindividually selected.

In a fourth aspect, the present invention is directed to a programstorage device readable by a machine, tangibly embodying a program ofinstructions executable by the machine to perform method steps forviewing violations identified by a design rule checker, the method stepscomprising: inputting text output from the design rule checker into asoftware program routine for viewing the violations; inputting designfile information into the software program routine; generating a subsetoutput file of the violations for a user to view; and editing the designfile based on the violations.

BRIEF DESCRIPTION OF DRAWINGS

The features of the invention believed to be novel and the elementscharacteristic of the invention are set forth with particularity in theappended claims. The figures are for illustration purposes only and arenot drawn to scale. The invention itself, however, both as toorganization and method of operation, may best be understood byreference to the detailed description which follows taken in conjunctionwith the accompanying drawings in which:

FIG. 1 depicts the overall process flow for the present invention.

FIG. 2 depicts a pop-up window of violations to view and available to bechosen by the user.

FIG. 3 depicts the pop-up window of FIG. 2 with a sample violationviewing along with a highlighted feature pertinent to the violation.

FIG. 4 depicts the pop-up window of FIG. 2 with general highlighting andboxing of first and second violation features.

FIG. 5 depicts the pop-up window of FIG. 2 with a bounding box around aregion pertinent to the violation.

FIG. 6 depicts the pop-up window of FIG. 2 having a box drawn to show afeature search region.

FIG. 7 depicts a portion of the pop-up window of FIG. 2 showing basichelper function soft-keys, including a “save line” feature.

FIG. 8 depicts an additional helper function pop-up window with examplesof helper function available to the user.

FIG. 9 depicts a sample viewing of the selection of a subset output filefrom the directory.

FIG. 10 depicts a sample violation pop-up window list showing the subsetof the overall list specified by the user to communicate with thedesigner.

FIG. 11 depicts sample instructions for the Cadence Allegro design tooladvising the user of the temporary layer created for viewing violations.

FIG. 12 depicts an example of a temporary layer created for viewingviolations within the CADENCE ALLEGRO design environment that can besafely removed without making permanent, destructive changes to theoriginal design.

FIG. 13 depicts an example of helper function that has a bounding box asits input.

FIG. 14 depicts a second example of a helper function where the user mayselect a function that has a feature name as its input.

DETAILED DESCRIPTION

In describing the preferred embodiment of the present invention,reference will be made herein to FIGS. 1-14 of the drawings in whichlike numerals refer to like features of the invention.

The present invention takes existing text output from a rule checker inappropriate input format, and automatically displays the text within thedesign tool using existing design tool capabilities, such ashighlighting, zooming, drawing box-regions, and the like. Information isgraphically associated with the rule checker text output. A graphicaluser interface output of the rule checker is then provided. Theinvention graphically displays the output of the rule checker includingthe informative text. Any violations are listed in a manner in whichthey can be individually selected. The output is displayed on a uniquelayer within the design tool so as to make no permanent changes to theoriginal design file. The layers may be safely deleted when no longer inuse. This process provides a user with means to annotate and output asubset file for use by other users and designers. For example, adesigner may then load and view a subset file using the presentinvention, without having to run the rule checker. Useful helperfunctions are also provided, which allow the user or designer to gainmore information about the design. These functions are generallyavailable in the design tool; however, their implementation wouldnormally involve a more intensive manual process.

Importantly, the present invention takes the output of the design rulechecker and graphically identifies each violation to the user usingdesign tool operations. The user selects from a list of violations,which may be presented in a pop-up window, and zooms the view to anappropriate level for the user to clearly see the violation, dependingon the type of information contained in the rule checker file. Thisprocess highlights and effectively draws a bounding box around anyviolation in question if applicable. The pop-up window is made tocontain information identifying the violation along with other pertinentinformation about it, such as the net name, component name, and thelike, which will aid the user in understanding more about the violation.The pop-up window also contains information about the checked designrule, which helps the user to understand the violation. This informationincludes identifying the parameters being checked and information as towhy these parameters are important. Importantly, the output file of thedesign rule checker must be in a format that can communicate with, andbe processed by, the present invention. The output file of the designrule checker is the input file for the Invention. The user applies therule checker text output to speed up and simplify the review of thedesign rule checker output.

The present invention generates an output file that allows the user tosave information related to identified violations in order to share theinformation with a designer or other user. In this process, the userrequests that a particular violation be saved. The resulting output filecontains only those violations that the user requested to be saved. Anew user reviewing this subset file can then view precisely what thefirst user experienced. The original file is preserved. Consequently,the creation of this subset file is repeatable for multiple, uniqueoutput files.

Normally, extensive user interaction is necessary to obtain additionalinformation about the violating feature or surrounding features. Thisinteraction generally requires a substantial number of keystrokes, whichneed to be frequently repeated. The process of getting this additionalinformation may, on occasion, cause the user to change the viewpoint ofthe design, either the magnification level, feature visibility, orlocation of the view port. The present invention affords multipleadvantages here. First, “helper functions” are automatically integratedfor common activities, such as zooming to a region, measuring cumulativedistance between multiple points, resetting visibility, and the like.This integration saves input time and removes input mistakes by reducingthe number of keystrokes necessary for input. Second, since a list ofthe violations is contained within a selectable popup window, the userneed only reselect the violation to return to the originally presentedview.

The issues addressed by the present invention enable a user to savesignificant time. Typically, timesavings can be upward of 75-90% of theoriginal, manual review time.

Overall Process Flow

FIG. 1 depicts the overall process flow for the present invention. Theinvention input file 6 is a software tool that provides a graphical userrepresentation for a printed circuit board design file 1 and the outputof a design rule checker 4. The overall application of the invention istypically as follows: The user applies rule checker parameters 3 againsta design file or some subset of the design file data 2 within a designrule checker 4. The rule checker 4 compares the design data 1, 2 againstthe rule checker parameters 3 and provides output to the user in textform 5 and in a standard file format specified for the input file 6. Thepresent invention then a “violation viewer” methodology 8 that generatesan output file 9 allowing the user to save information related toidentified violations. This includes the data from the design file 1,and uses the input file 6 to graphically identify the rule checkeroutput to the user.

When the user identifies particular violations that need to be sharedwith the designer, a portion of the “violation viewer” methodology 8 isused to create a subset output file 9 that contains only that violationinformation to be shared with the designer. If appropriate, a textversion of this output 7 may also be generated. The designer operatesthe “violation viewer” methodology 8 similar to the original user,applying the subset output file 9 against the design file 1, using thetext output 7 as an additional reference if needed. The designeridentifies and performs necessary design file changes 10 on the designfile 1. This process may then iterate through from the rule checkingprocess as many times as is deemed necessary by the user.

Upon initializing the software to perform the methodology of the presentinvention, the user is presented with a pop-up window 11 as shown inFIG. 2, which lists the violations reported 12 along with somedescriptive text 13 taken from the rule checker to identify the rulecheck performed. If the list 12 is longer than the window permits, ascroll bar 17 is provided to scroll through the list 12. The user mayselect a violation to be displayed, which will then be highlighted 1)either by selecting it with the mouse pointer, using the “up” and “down”arrow keys on the keyboard, or with the Prev(ious) 18 and Next 19clickable software buttons. For each violation, useful information suchas an identifier number 15 and violation description 16 is shown in thelist 12 as provided by the rule checker output 6. The graphicalrepresentation of the rule checker output 6 can be shown to the user ina variety of ways. The software for the present invention is designed tointeract with the design file software using the design file software'svarious capabilities.

A feature central to the violation 25 may be highlighted as depicted inFIG. 3. Where a violation contains a main description 16 and a secondaryfeature related to the violation 23, both highlighting of the mainfeature 25 and highlighting and/or the drawing of a small box around thesecondary feature 24 can be performed. This is shown in FIG. 4. If abounding region is pertinent to the violation, a bounding box ofprescribed distance may be drawn around the key feature 26. FIG. 5depicts a bounding box around the region. In this example, a box isdrawn around a component pin at a distance from all sides of the pin. Ifthe violation relates to the lack of a desired feature that should belocated within a region, a bounding box representing the checked regionmay be drawn 28, as depicted in FIG. 6. The box is drawn to indicate afeature search region based on a set of grid coordinates specified bythe rule checker. The box drawn 28 represents one grid box in theoverall grid. In addition to these graphical representationcapabilities, the invention methodology also provides the user with theability to output a subset list of the violations that need furthercommunication 7, 9. This output file is created with the “save line”software button 21 on the main pop-up window 11 as shown in FIG. 7. Oncecreated, the subset output 9 may be viewed graphically within the designtool. The user accesses this ability primarily through an additionalhelper function pop-up window 38 shown in FIG. 8. The helper functionsinclude an initial set “Goto Point”, “Get Distance”, and “Reset FindFilter”, and additional helper functions including “Start Vioviewer”,“Outline ON/OFF”, “Show Comp”, “Show Comp Info”, “Show Decaps”, “ShowPin”, “Show Net”, “Show Net Info”, “Show Seg”, “Get Layer Thick”,“Sublayer Thick”, and “Done”.

The “Goto Point” allows the user to input an x- and y-coordinate andzooms such that the selected coordinate is at the screen's center. The“Get Distance” allows the user to select two points on the screen,returning the distance between the selected two points. The “Reset FindFilter” resets the state of the selection feature. The “Outline On/Off”toggles the design element called “outline” to an on or off state. The“Show Comp” allows the user to input a component identifier, and zoomsthe display such that the component is at the center of the screen andhighlighted. The “Show Comp Info” allows the user to input a componentidentifier, and returns a pop-up window containing the componentproperties. The “Show Decaps” highlights decoupling capacitors connectedto the net specified by the user. The “Show Pin” takes the user input ofa component pin, and zooms so that the pin is in the center of thescreen and highlighted. “Show Net” takes the user input of a net, andzooms so that the net is in the center of the screen and highlighted.“Show Net Info” allows the user to input a net identifier, and returns apop-up window containing the net properties. “Show Seg” takes the userinput of a net segment, and zooms so that the net segment is in thecenter of the screen and highlighted. “Get Layer Thick” allows the userto select a layer identifier and returns the thickness dimension fromthe design data. “Sublayer Thick” allows the user to select a sublayeridentifier and returns the thickness dimension from the design data.“Done” closes the helper window.

Along with an initial set of helper functions 29, a soft-key button“Start Vioviewer” 31 is programmed to start the viewing of the inputfiles 6, 9. When this button is selected, a violation file selectorpop-up window 30 is presented as seen in FIG. 9. This window shows alist of files 33 that may be selected. The subset files are created asseparate files from the original input files. When the desired file isidentified, it may be selected by clicking on it, which initiatesloading it into the file path box 34. Alternatively, if the user knowsthe specific file path, he or she may type it directly into the filepath box 34. Referring to FIG. 10, once started, the present inventionoperates on the subset file 9 and shows a similar pop-up box 110 to theviolation list as shown previously. In this case, the violation list 120contains only those in the subset output file 9. This can be seen in theviolation list 120. FIG. 10 depicts the sample violation pop-up windowlist showing the subset of the overall list specified by a user tocommunicate with a designer.

Since the invention relies on interacting with the design file 1 withinthe design tool, the features 24, 25, 26, 27 shown in FIGS. 2-6 arecreated as design elements in the design file 1. In order to keep thesedesign elements 24, 25, 26, 27 from permanently altering the originaldesign file 1, they are created on a unique layer or class 37 within thedesign file 1, and can be deleted from the design file 1 withoutpermanently altering the original data. Instructions 35, 36 for removalof this layer or class 37 may be provided to the user throughinteraction with the design tool. FIG. 11 depicts sample instructionsfor the CADENCE ALLEGRO™ design tool, advising the user of the temporarylayer created for viewing violations that can be safely removed withoutmaking permanent, destructive changes to the original design. An exampleof this layer or class 37 within the CADENCE ALLEGRO design environmentis shown in FIG. 12. The layer in this example is labeled “VioView” 370.FIG. 8 showed an example of a number of helper functions 29 availablevia a pop-up window 28 within the invention. An example of anotherhelper function 290 is shown in FIG. 13. In this figure, the user hasselected a helper function 290 that has a bounding box as its input. Apop-up window 380 enables the user to specify the coordinates of arectangular box 390 that the invention can draw a bounding box about andzoom in magnification. FIG. 14 is a second example of a helper function290 a where the user may select a function that has a feature name asits input. This selection displays a pop-up box 400 in which the userspecifies a feature name 410. Typical operation of this helper function290 would highlight the feature and zoom the magnification to anappropriate level.

Alternative Embodiments

The description of the present invention has thus far been based onusing the invention to graphically display design rule checker outputthat is overlaid onto the design file within the design toolenvironment. Alternately, the invention may be used to output a formatthat is viewable in a different software program or in a common graphicsformat such as, but not limited to, JPEG, GIF, TIFF, BMP, HTML, and thelike. The above-identified figures are examples of the invention as usedwith the Cadence Allegro design tool. However, the invention is notlimited to one tool as long as design tool commands are driven by asoftware program, the invention can be used in any design tool. Throughthe use of a translator from one format set of instructions to another,the subset file or even the original design rule checker file can betranslated to work with a design tool other than the one originally usedto create the design.

While the present invention has been particularly described, inconjunction with a specific preferred embodiment, it is evident thatmany alternatives, modifications and variations will be apparent tothose skilled in the art in light of the foregoing description. It istherefore contemplated that the appended claims will embrace any suchalternatives, modifications and variations as falling within the truescope and spirit of the present invention.

1. A method of using text from a design tool to display an output to auser, said method comprising: graphically displaying said output fromsaid text of said design tool; graphically listing design ruleviolations; displaying said output as part of a software layer of saiddesign tool such that no permanent changes are made to any originaldesign file; requesting that particular violations be saved in a subsetoutput file; generating and annotating said subset output file for useby other users such that said subset output file contains only saidparticular violations said user requested to be saved; generating saidsubset output file in a form that allows said subset output file to beapplied against the design file; generating software help functionsallowing said user to gain information about design rule violations; anditerating this process using said subset output file through a rulechecking process as many times as necessary to remove said particularviolations.
 2. The method of claim 1 wherein said design tool is adesign rule checking system.
 3. The method of claim 1 wherein said textcomprises text output from said design tool.
 4. The method of claim 3wherein said text output from said design tool comprises an input filefor software implementing said method.
 5. The method of claim 1including representing said output as part of said software layer ofsaid design tool, and deleting said output when no longer required. 6.The method of claim 5 including having said software layer presented ina pop-up window display.
 7. The method of claim 6 wherein said pop-upwindow further includes information identifying said design ruleviolations, net name, component name, information relating to designrules.
 8. The method of claim 7 wherein said pop-up window furthercomprises the identification of parameters being checked along withinformation as to said parameters' importance.
 9. The method of claim 1including drawing a bounding box around any of said design ruleviolations.
 10. The method of claim 1 including loading and viewing saidsubset output file without running said design tool rule checker. 11.The method of claim 1 wherein said subset file includes savedinformation relating to an identified violation.
 12. The method of claim11 further including electronically sharing said saved information withdifferent users.
 13. The method of claim 1 wherein said software helpfunctions include highlighting, zooming, measuring cumulative distancebetween multiple points, changing viewpoints of a design, changingmagnification level, changing feature visibility, and changing locationof a viewport.
 14. The method of claim 1 further comprising reselectingsaid design rule violations to return to an originally presented view.15. A method of viewing violations identified by a design rule checkercomprising: inputting text output from said design rule checker into asoftware program routine for viewing said violations; inputting designfile information into said software program routine; generating a subsetoutput file of said violations for a user to view; requesting thatparticular violations be saved in said subset output file such that saidsubset output file contains only said particular violations said userrequested to be saved; generating said subset output file in a form thatallows said subset output file to be applied against the design file;editing said design file based on said violations; and iterating thisprocess using said subset output file through said design rule checkerprocess as many times as necessary to remove said particular violations.16. The method of claim 15 further comprising: inputting design data andrule checker parameters into a design rule checking tool; and performingdesign rule checking.
 17. The method of claim 15 including generating asubset text output file of said violations.
 18. The method of claim 15including representing said output as part of a software layer of saiddesign rule checker, and deleting said output when no longer required.19. The method of claim 18 including having said software layerpresented in a pop-up window display.
 20. A program storage devicereadable by a machine, tangibly embodying a program of instructionsexecutable by the machine to perform method steps for using text from adesign tool to display an output to a user, said method stepscomprising: graphically displaying said output from said text of saiddesign tool; graphically listing design rule violations; displaying saidoutput as part of a software layer of said design tool such that nopermanent changes are made to any original design file; requesting thatparticular violations be saved in a subset output file; generating andannotating said subset output file for use by other users such that saidsubset output file contains only said particular violations said userrequested to be saved; generating said subset output file in a form thatallows said subset output file to be applied against the design file;generating software help functions allowing said user to gaininformation about design rule violations; and iterating this processusing said subset output file through a rule checking process as manytimes as necessary to remove said particular violations.
 21. The programstorage device of claim 20 wherein said text comprises text output fromsaid design tool.
 22. The program storage device of claim 21 whereinsaid text output from said design tool comprises an input file forsoftware implementing said method.
 23. The program storage device ofclaim 20 including representing said output as part of said softwarelayer of said design tool, and deleting said output when no longerrequired.
 24. The program storage device of claim 23 including havingsaid software layer presented in a pop-up window display.
 25. A programstorage device readable by a machine, tangibly embodying a program ofinstructions executable by the machine to perform method steps forviewing violations identified by a design rule checker, said methodsteps comprising: inputting text output from said design rule checkerinto a software program routine for viewing said violations; inputtingdesign file information into said software program routine; requestingthat particular violations be saved in a subset output file; generatingsaid subset output file of said violations for a user to view such thatsaid subset output file contains only said particular violations saiduser requested to be saved; generating said subset output file in a formthat allows said subset output file to be applied against the designfile; editing said design file based on said violations; and iteratingthis process using said subset output file through said design rulechecker process as many times as necessary to remove said particularviolations.
 26. The method of claim 25 including generating a subsettext output file of said violations.